1. Field of the Invention
The present invention relates generally to scaffolding. More specifically, the invention is a safety rail adapted for use on a portable foldable construction scaffold.
2. Description of the Related Art
The related art of interest describes various safety devices for portable scaffolding, but none discloses the present invention. There is a need for an effective, economical safety rail device for closing the open upper region of a portable foldable construction scaffolding. The related art will be discussed in the order of perceived relevance to the present invention.
U.S. Pat. No. 495,810 issued on Apr. 18, 1893, to Daniel H. Iseminger describes an external extendible window bracket platform comprising longitudinally slotted bars on both sides of a platform having two transverse bars secured to each end thereof, and having a hand rail extending up from the platform at the window shaped to conform to the rectangular platform and supported by a centered frontal post. A curtain is draped around the handrail. The upper railing of the platform is distinguishable for requiring only a single piece of railing anchored at its ends on the platform by the window and a centered supporting outer post.
U.S. Pat. No. 3,212,605 issued on Oct. 19, 1965, to Robert L. Dickerson describes a portable collapsible wheeled scaffold having two telescopic parallel handrails. The apparatus is distinguishable for requiring a collapsible scaffold with two parallel telescopic handrails.
U.S. Pat. No. 5,121,812 issued on Jun. 16, 1992, to Minoru Ochiai et al. describes a folding wheeled scaffold unit having a second pair of parallel handrails added perpendicular to the scaffold's first parallel handrails by inserting in brackets on the first parallel handrails. The apparatus is distinguishable for requiring a second pair of parallel handrails.
U.S. Pat. No. 5,069,309 issued on Dec. 3, 1991, to Paul R. Swiderski et al. describes a rolling tower scaffold having an upwardly extending fenced-in platform portion comprising a pair of parallel longer railing pieces connected by a pair of hinged end gates. The apparatus is distinguishable for requiring hinged end gates.
U.S. Design Pat. No. 335,354 issued on May 4, 1993, t Bryant E. Phillips describes a ladder handrail comprising an incomplete extended loop attached to one side of a stepladder. The ladder handrail is distinguishable for its required looped shape and attachment to one leg of a stepladder.
U.S. Pat. No. 3,139,155 issued on Jun. 30, 1964, to Le Roy C. Skeels describes a U-shaped and forwardly bent ladder handrail comprising a retractable guard or safety rail that automatically locks in the raised, open, or unfolded position by links on the sides of the stepladder. The apparatus is distinguishable for requiring only a looped handrail attached to a stepladder.
U.S. Pat. No. 3,675,736 issued on Jul. 11, 1972, to William C. Roggie describes a guard rail assembly for a platform comprising a rectangular guard rail having four corner posts extending from the platform of a rectangular post assembly. The guard rail assembly is distinguishable for requiring only a conventional rectangular configuration.
U.S. Pat. No. 3,747,706 issued on Jul. 24, 1973, to David L. Paine et al. describes a portable wheeled folding stepladder riser apparatus for supporting a choir having an upright pair of frames supporting steps and having on top an upright rectangular safety rail supported by the two upright frames. The apparatus is distinguishable for requiring an upright rectangular safety rail.
U.S. Pat. No. 4,088,202 issued on May 9, 1978, to Clifford T. Costello describes a scaffolding cart comprising an electrically steerable scaffolding cart having a vertically positional platform and two parallel handrails transports and supports a workman. The apparatus is distinguishable for requiring two parallel handrails.
Japan Patent Publication No. 1-121460A published on May 15, 1989, to Akikazu Okawa et al. describes an installation method of a safety handrail in a frame trestle scaffold comprising a plurality of handrail units connected together and based in shield tubes on base plates fastened to joists. The handrail units can be telescopic in the horizontal direction. The handrails have an inverted U-shaped frame with upright side tubing. The safety handrails are distinguishable in having a fence-like structure.
Japan Patent Publication No. 2000-345715A published on Dec. 12, 2000, for Yasuyuki Okuda et al. describes a detachable handrail adaptable for different kinds of scaffolds comprising an inverted U-shaped frame with a median cross bar attached to a scaffold by end clamps. The device is distinguishable for requiring an inverted U-shaped frame with a cross bar and end clamps.
Japan Patent Publication No. 2001-73549A published on Mar. 21, 2001, for Yoichi Suzuki describes a hinged corner handrail for a corner section of a prefabricated scaffolding comprising an h-shaped member lying on its short side is hinged at its ends to the scaffolding and telescopically connected to another horizontal pipe. The handrail is distinguishable for being required to be hinged to one end of a scaffold.
Japan Patent Publication No. 2002-188282A published on Jul. 5, 2002, for Atushi Kondo describes a safety handrail for assembling and disassembling prefabricated scaffolding comprising a pair of expandable upright handrail support posts, an expandable horizontal handrail bar connecting the handrail supports, engaging members attached to the handrail supports, and clamps to hold the upright handrail support posts. The safety handrail is distinguishable for requiring only one side protection.
Japan Patent Publication No. 2002-220919A published on Aug. 9, 2002, for Atsushi Kondo describes a safety handrail for a pair of vertical frameworks for a scaffold comprising a vertical rectangular handrail with vertical and horizontal support members. The handrail can be moved vertically and clamped on the scaffolding frame. The handrail is distinguishable for requiring a rectangular frame.
Japan Patent Publication No. 2003-20787A published on Jan. 24, 2003, for Isao Moroto describes a safety fence device for a multi-layer scaffolding apparatus available for high-altitude work comprising a pair of connected horizontal rectangular tubes on vertical bearing leg portions and connected to strut bars that are slidable vertically. The safety fence device is distinguishable for requiring rectangular tubing connected by a bracket at their ends.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a safety rail for taper scaffolding solving the aforementioned problems is desired.